SU938135A1 - Method of determination of error in meter of ultrasound speed in materials - Google Patents

Description

(5) METHOD FOR DETERMINING THE UTILITY OF THE ULTRASOUND SPEED METER IN THE MATERIALS

one

The invention relates to indiscriminate quality control of materials, in particular building materials, and can be used to determine the metrological characteristics of measures of the speed of propagation of ultrasound in materials.

There is a method for determining the error of the ultrasound propagation velocity meter in materials by emitting an ultrasonic signal through protectors into an acoustic control unit with several sound conductors of various lengths, receiving an ultrasonic signal through protectors, which passed the sound ducts, measuring its propagation time, defined. the length of the difference in the length of the acoustic ducts and the difference in the times of propagation of ultrasound in them and the calculation of the error of the ultrasound velocity meter from the ratio

 p. e „Mk / ei-O.

where b is the error of the ultrasound propagation velocity meter; l |, t |, 1,1; -the length of the sound pipes and

the time of propagation of ultrasound in them, respectively, for the K-th and n-th sound pipes l.

The disadvantage of this method is the low accuracy of the error determination due to the instability of the acoustic contacts between the acoustic transducers of the ultrasound velocity meter being tested and the acoustic protectors of the unit, as well as the impossibility of creating the same contact conditions for different acoustic ducts.

Closest to the technical essence and the achieved result, the method of determining the error of the ultrasound velocity meter in materials, which means that the ultrasonic signal is emitted in a liquid sound path of a known length, receive this signal, measure the propagation time of ultrasound in the fluid core and determine the error of the ultrasound velocity meter by ratio:, C where 1, is the length of the liquid sound duct; t, s are, respectively, the time and speed of propagation of ultrasound in the fluid tube fZJ. The disadvantage of this method is the low accuracy of determining the accuracy of the ultrasound velocity meter, due to the fact that the acoustic characteristics of liquids (velocity, ultrasound attenuation coefficient, acoustic resistance, etc.) depend significantly on the change in its temperature. The purpose of the invention is to improve the accuracy of determining the error in measuring ultrasonic velocity bodies. This goal is achieved by the fact that, according to the method of determining the error of an ultra sound velocity meter in materials, which implies that an ultrasonic signal is emitted into a liquid duct of a known length, this signal is taken, the propagation time of ultrasound in a liquid duct is measured, the duct is a solid-state duct of known length with a known speed of propagation of ultrasound in it, thus forming a combined sound wire, radiating into a combined An ultrasound signal, receiving an ultrasound signal that passes through it, measures its propagation time in the Combined one. the acoustic duct and the determination of the error of the ultrasound velocity meter by the relation: (- - Pgde 1 and i is the length of the liquid and solid-state acoustic ducts, respectively;

 L

.-. SG

(2)

-L g; t .. and t- are the propagation times of the ultrasonic signal in the liquid and combined ducts, respectively; c is the propagation speed of ultrasound in a solid-state acoustic duct. The drawing shows a functional diagram of a device that implements a method for determining the error of an ultrasound velocity meter in materials. The device comprises a bath 1 filled with an acoustically conducting fluid 2i emitter 3 and an ultrasonic signal receiver k, mounted coaxially and fixed in the side walls of the bath at a distance 1. from each other, an ultrasound propagation velocity meter 5 and a solid-state acoustic duct 6. The essence of the method is next. The ultrasound propagation velocity meter 5, the error (f of which is necessary to determine, is connected to the emitter 3 and the ultrasonic signal receiver 4. Using the ultrasound propagation velocity meter 5, an ultrasonic signal is transmitted into the liquid acoustic conductor, an ultrasonic signal transmitted through it is measured and the ultrasound propagation time t is measured in the liquid sump, which, taking into account the error (Y, is equal to: Then in the bath 1 (in the fluid sump) put a solid-state sump 6 known to When the ultrasound propagation velocity meter is used to emit ultrasound into the combined duct, receive the ultrasound transmitted through it and measure the time t, the ultrasound propagation in the combined sump, equal, also taking into account the error and

Claims (1)

Formula of the invention the error of the ultrasound velocity meter according to a certain ratio, characterized in that, in order to increase the accuracy of determining S errors, a solid-state sound duct of known length with a known ultrasound propagation velocity is placed in the liquid sound duct, thereby forming a combined * 10 sound duct, radiated into the combined sound duct is an ultrasonic signal, receive the ultrasonic signal transmitted through it, and? measure the time of its propagation in the combined sound duct and determine the error of the ultrasound speed meter by the ratio 4) 14, where 1 is the length of the liquid and solid sound ducts, respectively; and t is the propagation time of the ultrasonic signal in the liquid and combined sound ducts; C is the speed of propagation of ultrasound in a solid-state sound duct. A method for determining the error of an ultrasound velocity meter in materials, which consists in emitting an ultrasonic signal into a liquid sound duct of known length, receiving this signal, measuring the propagation time of ultrasound in a liquid